Commercial data center operations use hard-wired communications systems to interconnect hundreds or thousands of servers, routers, memory storage systems and other end devices. In these data centers, fiber optic communications cables are often used to interconnect the end devices. Fiber optic communications cables are also sometimes used in dedicated communications systems that are set up by business and government entities in office buildings and other facilities (referred to herein as “office networks”) that enable computers, servers, printers, facsimile machines and other electronic equipment to communicate with each other, through a private network, and with remote locations via a telecommunications service provider.
In both data center operations and office networks, the fiber optic cables that are connected to the end devices are typically terminated into one or more fiber optic patching systems that may simplify later connectivity changes. Typically, a fiber optic patching system includes a plurality of patch panels, fiber shelves, bulkhead panels, termination boxes or other structures that each include a plurality of fiber optic adapters mounted thereon (herein these structures are referred to as “fiber optic adapter mounting structures” or simply as “mounting structures”). Fiber optic communications cables are used to connect each end device to one of the fiber optic adapters that are mounted on the patch panels, fiber shelves, cartridges or other mounting structures. Additional fiber optic cables are connected between the patch panels or fiber shelves. Connectivity changes are typically made by rearranging the fiber optic cables that run between two mounting structures in order to change the connectivity between end devices.
As is known to those of skill in the art, a fiber optic adapter is a coupling device used to connect a first fiber optic communications cable that is terminated with an appropriate mating connector to (1) a second fiber optic communications cable that is terminated with an appropriate mating connector; (2) a second fiber optic communications cable that is terminated with a secondary fiber optic connector but is capable of mating and alignment by way of hybrid and/or compatible features; (3) a device. Fiber optic adapters are used, for example, to align the terminations on two fiber optic cables so that communications path(s) are provided between the fiber(s) in the first cable and the mating fiber(s) in the second cable. The adapters may provide a mechanically stable connection that precisely aligns the mating optical fibers, protects the junction between the optical fibers, and preferably exhibits a relatively low insertion loss.
One difficulty with fiber optic patching systems is that there are presently a wide variety of different fiber optic adapters in use which, in some instances, are incompatible with each other and which may vary in size, shape and/or method of connection. These fiber optic adapters include, for example, SC, LC, MPO, ST and FC fiber optic adapters. As different end devices may include different types of fiber optic adapters, some mounting structures in the fiber optic patching system may need to have more than one type of fiber optic adapter mounted thereon.
FIG. 1 is a front perspective view of a conventional duplex LC fiber optic adapter 10. FIG. 2 is a rear perspective view of the duplex LC fiber optic adapter 10.
As shown in FIGS. 1 and 2, the adapter 10 comprises a body 20 having a front portion 30 (also referred to as the “senior end”) and a rear portion 40 (also referred to as the “junior end”). Ledges 22 are provided on the sides of adapter 10 at the interface between the front portion 30 and the rear portion 40. First and second plug apertures 32, 34 are provided in the front portion 30 of the adapter 10. Each of the plug apertures 32, 34 is configured to receive an LC fiber optic cable plug termination. As shown in FIG. 1, a length L1 of the front portion 30 may be greater than a length L2 of the rear portion 40.
As shown in FIG. 2, the rear portion 40 of the body 20 includes a rear surface that has first and second plug apertures 42, 44 that are each configured to receive an LC fiber optic cable plug termination. In the depicted embodiment, the side surfaces of the rear portion 40 include first and second cantilevered arms 36, 38 which are integrally formed with the body 20 and which form respective first and second snap clips. In another embodiment (not pictured), the first and second cantilevered arms may comprise one or more separate pieces of, for example, metal or plastic, that are physically attached to the body 20 to create a physical structure that functions as first and second snap clips. The first and second snap clips may be used to hold the LC fiber optic adapter 10 within an adapter collar (described below). Plug apertures 32 and 42 may be longitudinally aligned with each other, and plug apertures 34 and 44 may likewise be longitudinally aligned with each other. A first alignment sleeve (not visible in the figures) is positioned between plug aperture 32 and plug aperture 42 that acts to properly align the optical fibers of the plug terminations inserted into plug apertures 32 and 42, and a second alignment sleeve (not visible in the figures) is similarly positioned between plug aperture 34 and plug aperture 44 that acts to properly align the optical fibers of the plug terminations inserted into plug apertures 34 and 44.
Typically, an adapter collar is used to mount a fiber optic adapter such as adapter 10 on a mounting frame such as a patch panel, fiber shelf, termination box, bulkhead panel or the like. Herein, the term “adapter collar” refers to a structure that has at least one engagement mechanism that may be used to mount the collar on a mounting frame, and one or more openings that are each configured to receive one or more fiber optic adapters. FIG. 3 is a perspective view of a conventional adapter collar 50 that may be used to mount the LC duplex adapter 10 of FIGS. 1-2 on a patch panel or other mounting frame.
As shown in FIG. 3, the adapter collar 50 comprises a unitary body 60 that has a top surface 62, a bottom surface 64, opposed first and second side surfaces 66, 68 and a fiber optic adapter mounting cavity 70 that extends from a front 72 of the body 60 through to the rear of the body 60. The first side surface 66 includes a first cantilevered arm 76 that forms a first snap clip. The first side surface further includes a pair of ledges 78 that, in conjunction with first cantilevered arm 76, may be used to mount and lock the first side surface 66 of adapter collar 50 onto a mounting frame. The second side surface 68 likewise includes a second cantilevered arm 80 that forms a second snap clip and a pair of ledges 82 that may be used to mount and lock the second side surface 68 of adapter collar 50 onto the mounting frame.
As noted above, the adapter collar 50 may be used to mount an LC fiber optic adapter such as adapter 10 onto a mounting frame. FIG. 4 is a perspective view of an exemplary mounting frame in the form of a fiber optic patch panel 100. As shown in FIG. 4, the patch panel 100 comprises a frame 102 that includes a plurality of openings 104, each of which may receive a fiber optic adapter. Typically, adapter collars (e.g., adapter collars 50) are snap-clipped or otherwise mounted in each opening 104, and the fiber optic adapters (e.g., adapters 10) are then mounted in respective of the adapter collars. The frame 102 may comprise, for example, a stamped piece of sheet metal that is approximately one-eighth of an inch thick. Mounting apertures 106 may be provided on each end of frame 102 that may be used to mount the patch panel 100 onto an equipment rack (not shown in FIG. 4).
FIG. 4 also shows how one of the adapter collars 50 of FIG. 3 may be mounted in one of the openings 104 in frame 102. In particular, the front 72 of the adapter collar 50 is inserted into the opening 104 from the rear of the frame 102 until the first and second cantilevered arms 76, 80 snap into place on the sides of the openings 104 in frame 102. The duplex LC fiber optic adapter 10 of FIG. 2 may be mounted in the adapter collar 50 by inserting the rear portion 40 of fiber optic adapter 10 into the front of the fiber optic adapter mounting cavity 70. When the fiber optic adapter 10 is mounted in the adapter collar 50, and the adapter collar 50 is mounted on the patch panel 100, the fiber optic adapter 10 extends a distance D1 in front of the frame 102, and may also extend for a distance behind the frame 102.
As noted above, fiber optic patching systems may be used in both data centers and office building communications networks to facilitate routing fiber optic cables between end devices in an organized fashion, and to simplify the process for later making changes to the connections between end devices in these networks. FIG. 5 is a simplified schematic illustration of how fiber optic patch panels (or other mounting frames) may be used to form a fiber optic patching system in a data center.
As shown in FIG. 5, a plurality of servers 110-114 are connected by fiber optic communications cables 115-119 that are terminated with, for example, SC plug connectors to a fiber optic patch panel 120. In this particular example, the patch panel 120 is a Multi-fiber Push On (“MPO”) to single fiber patch panel that includes twenty-four single strand SC fiber optic adapters (which are located on the front side of patch panel 120 and hence are not visible in FIG. 5) and two multi-strand (here 12-strand) MPO fiber optic adapters 122, 124. Patch panel 120 may be used to aggregate a plurality of single strand fiber optic cables for connection to a multi-strand fiber optic cable.
“Backbone” multi-strand fiber optic cables 126 and 128 (12 strands per cable) are connected to the MPO adapters 122 and 124, respectively. These backbone cables 126, 128 are typically routed through the floor and/or ceiling of the data center, and have an MPO plug termination on each end thereof. A second MPO-to-single fiber patch panel 130 is mounted on another equipment rack that has two MPO adapters (not visible in FIG. 5) that receive the MPO backbone cables 126, 128, and twenty-four single strand SC fiber optic adapters 132 that are configured to receive single strand fiber optic cables that are terminated with an SC plug termination such as single strand fiber optic cable 134. The SC plug termination on the other end of cable 134 is plugged into a fiber optic adapter 142 on a rack-mounted network switch 140. The switch 140 provides a fiber optic communication path between the SC fiber optic adapter 142 on switch 140 that receives fiber optic cable 134 and a second SC fiber optic adapter 144 on switch 140. One end of a single strand fiber optic cable 146 that has an SC plug termination on each end thereof is received within the fiber optic adapter 144.
The fiber optic cable 146 connects the fiber optic adapter 144 on switch 140 to an SC adapter (not visible in FIG. 5) on a second rack-mounted MPO-to-single fiber patch panel 150. The MPO-to-single fiber patch panel 150 connects this single strand SC adapter to an MPO adapter 152. A backbone multi-strand fiber optic cable 154 that is terminated on each end with an MPO plug connector connects MPO adapter 152 to an MPO adapter (not visible in FIG. 5) on another MPO-to-single fiber patch panel 160. A single strand fiber optic cable 164 that is terminated on each end with an SC plug connector is plugged into an SC adapter 162 on the front side of the second patch panel 160 to connect SC adapter 162 to one of a plurality of memory storage devices 170-174 (device 170). Thus, as shown in FIG. 5, the servers 110-114 may be connected to the memory storage devices 170-174 through a series of patch panels, backbone cables, patch cords and a network switch.
As equipment is, for example, added, moved or replaced in a data center, and/or as services that are provided to particular pieces of equipment are changed, it may become necessary to make temporary and/or permanent changes to the interconnection scheme. For example, if memory storage device 170 in FIG. 5 is scheduled to be replaced with a new memory storage device, a server (e.g., server 110) that uses the first memory storage device 170 may need to be temporarily connected to a second memory storage device (e.g. memory storage device 171) until such time as the replacement for memory storage device 170 may be installed, configured, tested and brought online. The patching system depicted in FIG. 5 may provide a simple way of connecting server 110 to memory storage device 171 by changing the patching connections between, for example, the patch panel 130 and the network switch 140.
The interconnections between the various end devices, patch panels and switches of FIG. 5 are typically recorded in a computer-based log. Systems for automatically detecting and logging cabling connections between patch panels have been proposed such as, for example, the systems disclosed in U.S. Pat. Nos. 6,222,908; 6,784,802; 6,424,710 and 6,968,994. Some of these systems for automatically tracking patching connections employ intelligent patch panels that sense when cables are plugged into, or removed from, fiber optic adapters on the panel in order to automatically track and record in a computer-based log each change to the patching connectivity.